The prompt is the part that has human input. If the human’s input is not minimally creative, than the AI generated whole cannot be minimally creative. If the human’s input is minimally creative, the AI output will likely be minimally creative.
If you use software to position objects in a the frame, and then you ask an AI to generate the objects and a background with the framing that you specified, you will almost certainly have a copyrightable work, because deciding where things are positioned in a picture is enough to rise to the level of minimum creativity.
What matters is the human’s input. You can create uncopyrightable works using any tool, and you can use any tool to create copyrightable works. What matters is how much human expression is involved.